In theory, every passive tower is made for active bi-tri amping... you just have to remove the passive crossover, install new connectors, choose the active crossover and amplifiers of your choice, and voilá. It does involve a bit of diy and driver and speaker testing, but that is actually fun and teaches you a lot.
If you're looking for something ready to go, Burchardt has a couple of choices and another one on the way. Up the price ladder, D&D has the 8c, Kii has the Three, and of course you have the pro audio world with loads of options, many of which beat easily many of the 'audiophile' passive options out there that may be even much more expensive. Check the reviews for JBL, Genelec, Neumann and other pro monitors on this site.